Two years ago, Diaw wasn’t good enough to play for the worst team in basketball.

Now he’s the difference for what appears to be the best team.

Since Spurs coach Gregg Popovich inserted Diaw into the starting lineup for Game 3, San Antonio has outscored Miami by an absurd 40 points.

Diaw, waived by the lowly Bobcats in 2012 after losing the battle of the bulge, has been the biggest surprise of the playoffs. The 6-8 power forward averaged 11 points, nine rebounds and eight assists per 48 minutes during the two games played in Miami.

“Implementing Diaw into the lineup has given them another point guard on the floor,” LeBron James said after Thursday night’s 21-point loss in Game 4. “So Manu [ Ginobili], Tony [ Parker] and Diaw and Patty Mills on the floor at once, they’ve got four point guards basically on the floor at once. So all of them are live, and they all can make plays. So it’s a challenge for us all.”

With Diaw in the starting lineup, the Spurs have taken a tied series and turned it into a laugher; Diaw’s plus-minus in Miami was a crazy plus-35. Diaw has mastered the use of his still-burly frame, exploiting mismatches against smaller players in the paint.

“Boris pretty much does the same thing every night, as far as helping us be a smarter team at both ends of the floor,” Popovich said. “He knows what’s going on at all times.”

Said Diaw: “[Popovich] just told me that I was going to start the game [Tuesday] and try to be a facilitator out there, just trying to make plays for others and try to make the right decisions.”

DUNCAN’S LEGACY

The argument for Tim Duncan as the best power forward of all-time strengthens by the year. But what is inarguable: He is one of the premier playoff performers in NBA history.

Of course, his four titles (and three Finals MVPs) speak for themselves.

But with his 31 minutes played Thursday night, Duncan became the all-time playoff leader in minutes (8,869), passing Kareem Abdul-Jabbar for first on the list. Duncan also recorded his 158th career playoff double-double, passing Magic Johnson for the all-time mark.

Duncan’s 543 playoff blocks are already a record, and he is fourth in all-time postseason games played (233).

“It’s an honor to be in that position,” Duncan said. “Having won helps.”

THIS AND THAT

• Unless the Heat bucks history and reverses a 3-1 deficit, the Spurs are on the verge of winning five NBA titles in 16 years. Only three other franchises have achieved that feat: the Celtics (twice, in the 1960s and from the mid-’70s to ’80s), the Lakers (also twice, in the 1980s and the 2000s) and Michael Jordan’s Bulls (in the ’90s).
• The last time a team led back-to-back Finals games by 20 or more points was the 2002 Lakers, who built huge leads against the Nets in Games 1 and 2.
• The Spurs have won 11 playoff games this year by 15 or more points, another record.
• Popovich, when asked by a Turkish reporter Thursday night who would get his vote for Finals MVP: “Next question.”